Development of wheel weight reduction technology as a measure for improvement in the fuel efficiency of an automobile and improvement in the motion performance of a vehicle has been advanced. As an application of such technology, wheels have been developed in which fiber reinforced plastics (hereinafter, referred to as FRP) are used as a material, and particularly carbon fiber reinforced plastics (hereinafter, referred to as CFRP) including carbon fiber is used as a reinforcement material.
For instance, Japanese Unexamined Patent Application Publication (JP-A) No. 2-261630 discloses a method by which the rim of a wheel is manufactured by so-called filament winding molding method (FW method) in which filament reinforced fiber, which is impregnated with a resin, is wound around a mandrel. According to the method described in JP-A No. 2-261630, a rim is formed by rotating a rim-shaped mandrel to wind a filament around the mandrel.
The FW method described in JP-A No. 2-261630 is one of the techniques that take advantage of the strength of reinforced fiber. On the other hand, a technology has been developed, in which when an overall convex shaped member such as a gas tank is created by the FW method, a great number of continuous fiber reinforced plastics is provided in an axial direction, thereby reducing the time taken to laminate the plastics. However, there is a problem in that when the continuous fiber reinforced plastics is provided in a concave shaped member such as a rim of a wheel, it is difficult to guide the continuous fiber reinforced plastics into the mold of the wheel.